A peer-to-peer (P2P) wireless network is a distributed network architecture in which a number of peers or nodes can communicate with each other without a centralized controller or server (e.g., an access point or a base station). Examples of a P2P device (peer) include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a notebook, a netbook, a smartbook, a smartwatch, a personal digital assistant (PDA), a satellite radio, a global positioning system (GPS) device, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a sensor, or any other similar functioning device with P2P wireless communication capability. A peer can supply resources to, or consume resources from, other peers.
Before the peers can communicate with each other and form a P2P network, a peer needs to discover other peers first according to a discovery protocol. Two categories of discovery protocol are synchronous discovery and asynchronous discovery. Synchronous discovery protocols typically utilize a global clock, and all peers can wake up periodically or at a predetermined time (e.g., at substantially the same time) in reference to a timing signal from the global clock in order to discover each other.
However, in some scenarios or applications, it may not be desirable or practical to provide a global clock or timing signal thereof. In such cases, an asynchronous discovery protocol may be used when a global clock is not available or desirable. In an asynchronous discovery protocol, a peer may periodically (or at a predetermined time) wake up to scan for other peers in its communication range. If the peer wakes up more frequently and/or scans for a longer period, the probability of finding another peer will be increased at the expense of increased power consumption of the peer. On the other hand, reducing the frequency and/or duration of scanning can reduce power consumption of the peer.
While some existing wireless communication standards support asynchronous discovery (e.g., Wi-Fi Direct and Bluetooth Low Energy), they only work for two peers discovering each other. It is desirable to advance and enhance the state of the art in P2P wireless network with three or more peers.